Need advice on large room design

Doing a major remodel and now have the opportunity of building my audio room using Fibonacci based dimensions.

My room measures 19'3" x18'3" and current ceiling maxes out at about 14 feet.

1) I have the Cardas info on Trapagon room design and have designed a room is approx 19 long and has a wall on the speaker side that is approx 7'10 tall 12 wide. on the wall behind the listener has dimensions of 9'2" tall and 15'3" wide.
2) Walls and ceilings will be 1/2 inch drywall.
3) Cardas design includes sn opening in the ceiling that has a cutout in the ceiling that has insulation covering it and hidden with some type of cloth to dress it up a little.
4) Floors will be good quality carpet.

I am hoping to get some advice on this design and suggestions on other designs that I might use in this large space.
You might consider engaging the services of a professional acoustician, so that your efforts are directed by someone who really knows what they're doing. This is the sort of project where intelligent choices made early on are of great value, but mistakes made early on may well be prohibitively expensive to later correct. My recommendation would be Jeff Hedback, of Hedback Designed Acoustics - he's a multiple-award-winning studio designer who still does work in home audio at very reasonable rates.

I also highly recommend Jeff Hedback. He knows what he is doing and has designed some amazing stereo rooms, including mine :-).
Again for Jeff, he did my room...
Great recommendations